Bill, the hole in the roof idea is not a good one. At least I would never consider it in my home!!
Are you windows not able to function where you create a draft or air flow in the home?
Bill, there are in restuarants, where they want to remove smoke and interior air with fresh, wall mounted ducts like those thermostat controled roof vents. They duct downward and fit in the walls both interior and exterior.
I have never seen this in a home and don't know how it would look and how it would affect market value in case you decided to move some day.
I would need to think the following: resale value, security, leaking, wall damage, and whether it really worked to your satisfaction.
I would just open the windows and use the AC when needed.